How does the I Ching work? We can consider a variety of alternatives:
In our materialistic society, we can think that the I Ching is answering in an inconsistent way, and that we are over-interpreting its answers. Even so, the comments are based on philosophical reflexions which are enough to make us evolve in everyday life. In other words, even if the answers are irrelevant, consulting the I Ching will provide us an opportunity to think about larger philosophical concepts, that may inspire us in everyday life.
The adherents to this theory consider that the comments have been written in such a way that they can answer to all circumstances. For example, "It is important to think before acting." would be an advice that could satisfy any question. However such a statement does not withstand a thorough analysis of the comments. To give just one example, the line 5 of the hexagram 43 : "Others return because one didn't want to continue.". This comment is clearly about the return of an unwanted situation, thus it would not be adapted to new situations.
Of those who consult the I Ching regularly, some think that our brain has unsuspected resources and would be able to answer by itself to our inquiries. Thus when we handle the yarrow sticks, it would be our subconscious that would guide us toward the answer. It's an interesting theory, but it presupposes that we consult the I Ching only by means of yarrow stick, or at most with coins. It is undermined by the emergence of the readings done with a computer. Indeed, if our brain can lead us without our knowledge to the selection of specific sticks, having an influence on a computer located several hundred miles away becomes entirely unrealistic.
Synchronicity has been theorised by Carl Gustav Jung. Here, our brain does not play the leading role but consulting the I Ching would be like looking at a compass that would indicate our position in the spirit of the times. It is a theory that is widely accepted these days, because there are many examples of synchronicity.
Finally, that would be the simplest explanation. Our ancestors consulted oracles when they had important questions to address. Notably, the Pythia of Deplhi. Here the I Ching would be a channel between us and the divine.
As you can see, there are many differing theories. These are not neutral because selecting one will affect the nature of the questions that you will ask. Maybe do you have a different opinion on the matter? In this case do not hesitate to share it by commenting. You can also consult the I Ching about these matter.